I am confused and a little frustrated with my new ob. My last 3 pregnancies ended before 34 weeks due to preterm labor and delivery. All my babies are now healthy. I started the 17p injections at 16 weeks my last pregnancy which was the first time i took them. I got one every week(well, i was suppose to, i got snowed in for 3 weeks straight and missed a few.) I went in at 16 weeks this time and was expecting to get my shots started and my ob didnt mention the shot, we havent discussed it at all before, but i have with his nurse and i was under the impression that i would be starting them at 16 weeks like last time. He doesnt want me to start them until 20 weeks. I am so mad. I also got bi-weekly cervical length checks and he wants to do one a month. I am just worried about starting the shots too late. since i missed 3 shots in a row last time, i only mad it to 33 weeks last time which is 1 week more than the one before it. i just dont know what to think. does anyone else take these shots or has before, and when did you first got an injection?